Download a copy of the datasheet (if you haven't already) and look at the pin descriptions. They will have as part of the naming - PB0, PB1,PB2..., PC0, PC1,PC2..., PD0, PD1, PD2, PD3... and such. these are the port groupings. Then map those groupings to you setup and to that chart and you should have a pretty good idea whether you are pushing the current limits.
Page 2 of the datasheet shows the pinouts and names them all.
And here is the datasheet.http://www.atmel.com/dyn/resources/prod_documents/2549S.pdf